INNOVATIONS IN DEVICE THERAPY: Subcutaneous ICDs, Leadless Pacemakers, CRT Indications David J Wilber MD Loyola University Medical Center Disclosures: ACC Foundation: Consultant; Biosense / Webster: Consultant, Investigator; Medtronic: Consultant, Investigator
TRANSVENOUS ICD LEAD ISSUES TV ICD lead failure estimated at 0.68%-3.75% annually Lead survival at 2 years: 91-99% Lead survival at 5 years: 81-98% Lead survival at 8 years: 60-95% Up to 1/10 PM implants associated with adverse events Lead related (dislodgement, fracture, insulation failure, infection, cardiac perforation, venous occlusion, tricuspid regurgitation) Surgical pocket or generator related (skin erosion, hematoma, infection)
SUBCUTANEOUS ICD Indications Current indication for ICD implantation Not suited for pts who need Pacing for bradycardia Pacing for VT CRT Initial target populations Unfavorable anatomy, venous occlusion Prior transvenous device infection or high risk for infection Younger patients with need for lifelong therapy
DEVICE / IMPLANT CONSIDERATIONS Surface ECG screening Sensing vectors Minimal programming Unconditional zone Conditional zone morphology algorithms to discriminate SVT, cardiac signal oversensing DFT testing at 65 J Device delivers 80J Large PG size (60-70 cc) Can provide 30 s post shock demand pacing Episode EGM storage (not remote monitoring)
EFFORTLESS REGISTRY: REAL WORLD EXPERIENCE 472 pts, mean 18 mo f/u Age 49+18 yr LVEF 42+19% 63% primary prevention Heart disease: Ischemic (37%) Channelopathy/IVF (21%) HCM (8%) Other nonischemic CM (23%) Device infection 4%, 2.2% required explant One arrhythmic death Lambiase et al, EHJ 2014; 35:1657-1665
S ICD FUNCTION pocket hematomas 0.4% of pts Superficial infection treated conservatively in 0.3% of pts infection requiring device removal or revision occurred in 1.7% of pts 882 pts followed for mean of 651 days A total of 111 VT/VF episodes treated in 59 patients. Single shock successful in terminating VF in 90.1% of episodes, and 98.2% of VT/VF episodes after 5 shocks Burke et al, J Am Coll Cardiol 2015. 60:1605-1650
Lead complications Appropriate Shocks Infection IAS: SVT Device Failure IAS: oversensing JACCEP 2017: online before print
PRAETORIAN TRIAL Olde Nordkamp et al Am Heart J, 2012; 163:753-760 Noninferiority randomized comparison of single chamber TV-ICD vs S-ICD Primary endpoint: composite of devicerelated complications and inappropriate shocks Secondary endpoints: Device related complications Inappropriate shocks Appropriate shocks QOL, MACE, death, syncope Target enrollment 700 pts First enrollment 2/2011 Estimated completion 2018
LEADLESS TRANSVENOUS PACING Up to 1/10 PM implants associated with adverse events Lead related (dislodgement, fracture, insulation failure, infection, cardiac perforation, venous occlusion, tricuspid regurgitation) Surgical pocket or generator related (skin erosion, hematoma, infection) Small (1cc) self contained devices with encapsulated battery, electronics, and electrodes have been developed Implantation via a transfemoral venous deliveryretrieval device with fixation in the RV Current devices for single chamber pacing indication only
LTP: SJM NANOSTIM Dimension 4.2 X 0.6 cm Active fixation, rate adaptive Successful implant 504/526 pts (96%) Implant time 47+25 min 6 mo adverse event rate 6.7% 1.6% perforation 1.1% dislodgement 0.8% new device for elevated pacing threshold Reddy et al, New Engl J Med 2015; 373 (12):1125-1135
LTP: MEDTRONIC MICRA Dimension 2.6 X 0.7 cm Rate adaptive, APC Passive fixation Successful implant 719/725 pts (99%) 6 mo adverse event rate 4% Perforation or effusion 1.6%, elevated threshold requiring revision 0.2% no dislodgements Reynolds et al, New Engl J Med 2015; DOI 10.10561
FUTURE PERSPECTIVES Unresolved issues: Battery longevity Long-term stability of pacing parameters Long-term ease of removal Potential integration into more complex devices JACC 2015; 65:2207
CURRENT CRT INDICATIONS J Am Coll Cardiol 2012. 60:1297-313
CRT BENEFIT IN NON-LBBB Cunnington et al, Heart 2015; 101: 1456-1462
WOMEN AND CRT Zusterzeel et al, JAMA Intern Med 2014; 174:1340-1348
CRT FOR NON- LBBB AND LONG PR INTERVALS MADIT CRT SUBSTUDY Kutyifa et al, Circulation A&E 2014; 7:645-651
NEW DIRECTIONS IN CRT Clinical response rate ~ 70%, objective indices (LVEF improvement, reduced ventricular volumes) in ~ 50% Practical considerations % biventricular pacing as close to 100% as possible Major issues are ventricular ectopy and AF Assure LV contribution to pacing on surface ECG Quadripolar leads improve transvenous lead placement success, may be associated with reduced mortality Targeted placement at site of latest LV activation (electrogram timing) or contraction (LV strain imaging) Endocardial lead placement appears to produce better hemodynamic response, and allows tailoring to individual abnormal contraction patterns (AL-SYNC, WISE-CRT)
SUMMARY Use of Subcutaneous ICD expanding rapidly High effectiveness for sensing and terminating ventricular arrhythmias has been maintained Adverse events declining with experience Initial experience with leadless pacemakers promising, longer follow-up needed, size of target population unclear CRT: new twists Gender interaction with QRS duration and efficacy Possible benefit in non-lbbb with long PR intervals